Interpreting MIL-PRF-19500 (Performance Spec, Semicon Dev) - What is LTPD of 20 - ???

[mick4irl]

Hello -

I am not familiar with LTPD (Lot Tolerance Percetage Defect). In the part specifications it calls out group A, B, and C. We are testing to satisfy group A, but group B indicates a LTPD of 20 - ??? Can anyone shed some light on this???

If LTPD is 20 and referencing MilStat 19500 allows 0 failures - what would be the sample size?

Any and all help is appreciated. thank you.

Mr. McG

 

[e006823]

Re: Interpreting MIL-PRF-19500 (Performance Spec, Semicon Dev) - What is LTPD of 20 -

Hello -

I am not familiar with LTPD (Lot Tolerance Percetage Defect). In the part specifications it calls out group A, B, and C. We are testing to satisfy group A, but group B indicates a LTPD of 20 - ??? Can anyone shed some light on this???

If LTPD is 20 and referencing MilStat 19500 allows 0 failures - what would be the sample size?

Any and all help is appreciated. thank you.

Mr. McG

Where are you getting the LTPD of 20 for Group B from?

Regards,

 

[mick4irl]

Re: Interpreting MIL-PRF-19500 (Performance Spec, Semicon Dev) - What is LTPD of 20 -

E006 - The LTPD of 20 is from Group B as per the customer's spec./requirements. I am having trouble determining the sample size.

 

[sfkevin]

Re: Interpreting MIL-PRF-19500 (Performance Spec, Semicon Dev) - What is LTPD of 20 -

Mr. McG

You have to reference the actual slash sheet for the part you are testing and class, JANS, JANTXV, JANTX, and JAN. In MIL-PRF-19500 Rev N look at Table E-V Group A test QTY.

 

[e006823]

Re: Interpreting MIL-PRF-19500 (Performance Spec, Semicon Dev) - What is LTPD of 20 -

E006 - The LTPD of 20 is from Group B as per the customer's spec./requirements. I am having trouble determining the sample size.

If this is a compliant component then I believe that section 3.1 of 19500 addresses the use of LTPDs. You should use the appropriate table in appendix E (depending on device class JANS, JAN, JANTX, JANTXV) for group A and group B.

If you customer isn't purchasing a compliant component then Table E1 contains the LTPD sampling plans. The top row labeled "Maximum percent
defective or lambda, accept number (c) (r = c + 1)" are the LTPDs. For a LTPD of 20 the sample size would be 11, C= 0 or 18 C= 1.

Either way you should clarify requirements with your customer.

Regards,